Muti-tool, $30:
http://www.midwayusa.com/viewproduct...tnumber=885858
Action block kit, $40:
http://www.midwayusa.com/viewProduct...tNumber=829522
Those, along with some punches, are all you need to assemble any AR15 upper or lower. If you are just doing an upper, you can buy it with the dust cover and forward assist already installed and do not even need the punches. For $70, you can put together all the AR15's you want, along with your friends. It will also come in handy if you decide to change things up down the road. I know I'm always switching out barrels/FF tubes, etc. One more thing, I have a strap wrench that I got from Lowes, which really makes tightening FF tubes easier:
http://www.lowes.com/pd_253674-16878-50540_4294936478+5003718+5003697_41_?productId=107 2405&Ns=p_product_prd_lis_ord_nbr|0||p_product_qua ntity_sold|1&pl=1¤tURL=%2Fpl_15%2B25_4294936 478%2B5003718%2B5003697_41_%3FNs%3Dp_product_prd_l is_ord_nbr|0||p_product_quantity_sold|1&facetInfo= 2%20-%203|$15%20-%20$25
It's not entirely necessary, but it also has other uses around the house, so not a bad investment.
Regards,
-Dan